Method and apparatus for surface cleaning



Jan. 16, 1968 R p sc g o ET AL 3,364,067

METHOD AND APPARATUS FOR SURFACE CLEANING 5 SheetsSheet 1 Filed Dec 24, 1963 5 R 0% mmw ovm m lw N 6F- m e v." f m c h N W W om- E W n w m9 o M ..m o: o: o r vR A 09 N9 \oin V mm; 04. N5 II M vo/m mom Q VI L 9w mom mom on 9m .08 0mm mNN ATTORNEYS Jan. 16, 1968 R PlSClTELLQ ET AL 3,364,067

METHOD AND APPARATUS FQR SURFACE CLEANING Filed Dec. 24, 1965 3 Sheets-Sheet 2 INVENTORS Robert A. Plscltello Arthur E Petit MW $2M ATTORNEYS Jan. 16, 1968 p Lo ET AL 3,364,067

METHOD AND APPARATUS FOR SURFACE CLEANING Filed Dec. 24, 1963 3 Sheets-Sheet 3 FIG. 4

INVENTOR5 Robert A. Piscirello Arthur E. Pefit F /SZIZM WLW ATTORNEYS United States Patent 3,364,067 METHOD AND AlPARATUS FOR SURFACE CLEANING Robert A. Piscitello, Montville, and Arthur E. Petit, Hadlyme, Conn, assignors to General Dynamics Corporation, New York, N.Y., a corporation of Delaware Filed Dec. 24, 1963, Ser. No. 333,082 15 Claims. (Cl. 134-22) ABSTRACT OF THE DISCLOSURE Method and apparatus for cleaning internal surface of object having open and closed ends featuring successively introducing fluid under pressure and evacuating the internal surface at predetermined intervals during rotation of object.

The present application concerns a method and an apparatus for cleaning surfaces. Disclosed herein is a novel method and a novel apparatus for cleaning internal sur faces of hollow objects, particularly those objects having internal surface areas which are not readily accessible. Specifically, the invention describes the cleaning of tubes by the alternate application of pressurized fluid and the evacuation of the space adjacent to a surface, while moving the surface in specific relation to periods of applying fluid and evacuating.

Complete cleaning of peculiar-shaped objects historically has presented problems. One of the most effective Ways of cleaning is to contact a surface with a solvent and to remove the solvent. After the solvent has reached every portion of the surface, and after the solvent is removed, the surface is said to be cleaned. When the area to be cleaned is readily accessible, no undue problem is encountered. When the surface is uneven or when the interior of an object is involved, cleaning problems are increased because of the difficulty encountered in reaching the entire area. Restriction of access to an interior surface and extension of the surface away from the point of access greatly enlarge the difliculty and obstruct complete cleanmg.

Foreign matter, oil and other organics are disagreeable in piping systems. Dirty valves and gages present a source of contamination to all sealed systems. Moreover, contaminants in the form of oil are hazardous, due to the natural phenomenon of combustion of oil and oxygen in pressurized oxygen systems and the danger of spontaneous ignition in high pressure air systems. Because of the re quirement for total removal of all contaminants, the cleaning of the interior of closed-end, curved tubes of gages which are used in such high pressure systems becomes an exceedingly diflicult matter. Surface cleaning is improved when the solvent employed is under pressure. The cleaning process is further improved if the solvent can be conveniently removed by vacuum.

Thus, the present invention attacks the ditficult problem of cleaning an interior surface which is not directly accessible by using a novel method of successive applications of pressure and of vacuum. In addition, the entire surface is controllably moved during the successive applications in order to enhance the contacting of the entire surface by a pressurized solvent and in order to greatly improve characteristics of its removal.

Accordingly, an objective of this invention is to provide a method and apparatus for the efficient and complete cleaning of a surface.

Secondly, this invention reveals a novel and eflicient method and apparatus for removing foreign matter from a confined interior surface.

3,364,067 Patented Jan. 16, 1968 A third object of the invention is to provide a process for the complete interior cleaning of an elongated tube.

Another object of this invention is to provide a novel process and apparatus for cleaning internal surfaces of semi-closed objects having restricted access, especially for cleaning those objects having interior surfaces to which there is no direct access.

Another object of this invention is to provide a process and apparatus for the cleaning of hollow bent tubes which are closed at one end.

A remaining object of this invention is to provide a novel process and apparatus for the Grade-A cleaning of Bourdon tubes.

These and other features and objectives of the invention will be evident from the ensuing description and drawings, in which:

FIGURE 1 is a schematic representation of a suggested operational relationship of several elements for perfecting the novel cleaning process described in this application.

FIGURE 2 is an exploded View of fluid handling elements of the gage cleaner, illustrating a three-Way sole noid valve, swivel, and gage connection.

FIGURE 3 is a schematic front view of a Bourdon tube mounted on the gage cleaner, illustrating segments of rotation in which the gage is pressurized and evacuated.

FIGURE 4 is an over-all perspective view of a suggested commercial embodiment of the apparatus.

Referring to the drawings, FIGURE 1 reveals an arrangement of apparatus designed to execute the novel process herein disclosed. T-shaped connector terminates in opposite ends 104 and 106, which are configured to receive fluid carrying pipes or tubes. Terminal 102, which receives objects to be cleaned, laterally projects from connector 100 intermediate its ends 104 and 106. In the present case, end 106 is stopped with removable plug 110, and terminal 102 of the T joint is configured to receive the base of Bourdon tube Alternatively, end 102 may receive adapters (not shown) which may in turn be configured to hold a myriad of objects to be cleaned.

End 104 of connector 100 engages swivel pipe in a fixed relation so that connector 100 may turn with the swivel pipe. The remaining end of pipe 140 is mounted for rotation in swivel 150, which acts as a bearing. Sprocket 314 is fixed on pipe 140 intermediate its ends to function as a driving gear for pipe 140 and connector 100.

The opposite end of swivel is connected to threeway solenoid valve 200 by pipe 160. Solenoid valve 200 selectively interconnects a source of cleaning fluid 220 or exhaust line 230 to pipes and 140, and, consequently, to gage connector 100 and its coupled gage 120.

Pressure to apply cleaning fluid to the object to be cleaned may be supplied by elevating cleaning fluid tank 220. In order that no vacuum be created therein, tank 220 is vented at 222. Alternatively, or additionally, static pressure head may be augmented by removing vent 222 and adding pressure through the vent duct. Augmenting pressure may stem from any controlled source such as regulated shop air. As a second alternative, fluid from tank 220 may be urged into the object to be cleaned by the vacuum that exists in the system immediately before the fluid is released. Sight glass 224 reveals the level of liquid 225 in order that the supply tank may be kept sufliciently full throughout the cleaning operation.

A vacuum is pulled in exhaust line 230 by jet pump 240, using shop air 250. Discharge line 260, leading from the jet pump 240, exhausts into the atmosphere or into a gravitational collection sump (not shown). The amount of pressure reduction in exhaust line 230 is indicated on gage 234, which is coupled to line 230 by sampling line 232. The precise reduction of pressure in line 230 may be 0 controlled by valve 252 in shop air supply line 250.

In order to selectively apply pressurized solvent or vacuum to the object to be cleaned, solenoid switch 200 is controlled by cam operated normally-open microswitch 330. In its energized position microswitch 330 causes solenoid valve 200 to operate, interconnecting fluid supply line 210 with gage supply pipe 160 and gage 120, which is being cleaned. Conversely, in its de-energized position, microswitch 330 leaves solenoid valve 200 in its dormant state, in which exhaust line 230 is connected to the connector 100. Thus, when no electrical energy is supplied the solenoid valve couples connector to jet pump 240, and shop air establishes a suction in the connector.

Cam 320, which operates microswitch 330 through cam follower 322, is directly mounted on shaft 308 of motor 300. Also directly coupled to the motor shaft is driving sprocket 310, which engages chain 312. Chain 312 drives sprocket 314, which is fixedly mounted on swivel pipe 140. In order that the solenoid valve operate in precise relationship to the turning of the object to be cleaned, driving and driven sprockets, 310 and 314, are of equal dimension. Thus, by mounting cam 320 directly on motor shaft 308, switch 330 and, consequently, solenoid valve 200 are synchronized with the rotation of pipe and with the rotation of the object to be cleaned, which is thereon mounted.

In order that number of rotation-s of the object to be cleaned may be accurately recorded, an electric counter 360 is employed. Upon each rotation of the shaft, cam 340, which is mounted on motor shaft 308, activates microswitch 350 through cam follower 342. When movable contacts 352 interconnect fixed contacts 354, electric counter 360 advances one indication.

As may be seen at the right-hand side of FIGURE 1, electric power lines 304 and 306 supply motor 300 and are interconnected to supply solenoid switch 200 and electronic counter 360. Interconnecting the power lines at 305 and 307 allows the total operation of the apparatus to be controlled by off-on switch 302.

Turning to FIGURE 2, primary fluid supply elements are shown in an exploded relationship. Solenoid valve 200 selectively interconnects either cleaning fluid line 210 or exhaust line 230 with a rigidly mounted supply line 160. Swivel union receives fixed supply line and rotatably mounts swivel pipe 140. Connector 100 is secured at the end of swivel pipe 140 to receive the object to be cleaned. Sprocket 314 is fixed to swivel 140 intermediate swivel union 150 and connector 100 to impart rotation to the latter. Laterally extending terminal 102 of connector 100 receives the threaded base of Bourdon tube 120. Alternatively, an adapter (not shown) may be received in intern-ally threaded terminal 102 to receive other valves, tubes and pipes having peculiar end construction.

Plug 110 is removably secured in the exterior end of connector 100. Removing the plug facilitates direct access to the interior of pipes 140 and 160 in order to facilitate their cleaning or the removal of obstacles. Moreover, replacing plug 110 with a conventional male-threaded nipple (not shown) permits the interconnection of a plurality of devices similar to connector 100. Consequently, many objects may be cleaned in the same operation.

In order to best clean a Bourdon tube, it is mounted with the plane of curvature of tube 124 perpendicular to the axis rotation of swivel pipe 140. The most complete cleaning is achieved when sealed end 126 of tube 124 points in the direction of rotation.

FIGURE 3 illustrates optimum portion of the rotation of a Bourdon tube to respectively effect its filling with cleaning fluid and its evacuating. As has been previously indicated, tube 124 is mounted with its plane of curvature perpendicular to the axis of rotation and is rotated in the direction of the free end 126 of the tube. Cam 320 is cut to close miscroswitch 330 at a point in the rotation of motor shaft 308 corresponding to a point in the rotation of swivel 140 when the neck 123 of tube 124 is vertically oriented. Consequently, at this point, the solenoid valve is energized, and filling of the system begins. Filling continues, as indicated by the phantom lines in FIGURE 3, until tip 126 of tube 124 crosses a vertical line depended from the axis of rotation. At that point cam 320 allows microswitch 330 to assume its normally-open position, de-energizing solenoid valve 200 and connecting pipes 140 and 160 to exhaust line 230. Cycling the steps of filling and evacuating is repeated until the gage is clean. Experience indicates that twelve cycles are satisfactory for most Bourdon tubes.

The method of cleaning has been disclosed for use with a Bourdon tube in the interest of consistency. It will be obvious to one skilled in the art, however, that the method may be adapted for cleaning an object of any given shape by selecting proper segments of rotation for respectively applying pressure and vacuum.

FIGURE 4 represents an efiicient laboratory embodiment of the above-described apparatus for effecting the cleaning process herein disclosed. Body 400 is preferably made of a light aluminum alloy plate. Alternatively, the case may be made of any durable material. Five apertures in face 410 receive the only fittings of the apparatus which are necessarily accessible. Swivel pipe 140 extends through a bearing sleeve in the face to receive connector 100 upon which gage 120 is mounted. Fluid level indicator 224 is mounted opposite the supply tank adjacent the top of container 400. Its operational counterpart, vacuum gage 234, is juxtaposed for visual accessibility. Electric counter 360 is mounted on the reverse of face 410 in order that the indicator 362 of counter 360 may be read through face 410. Indicated cycles may be returned to zero by knob 364 which extends through side 420 of body 400.

For easy access to internal parts of the apparatus a cover is pivoted at hinge 412. Elements in the rear of the gage cleaner are exposed by opening the back, which is mounted by a similar hinge (not shown). Through side 420 extend electrical connection 301 and discharge line 260. The latter, of course, may lead to a drain or collection sump. A shut-off valve 262 is provided to prevent internal contamination of the pipes in long periods of non-use.

An off-on switch 302 starts motor 300 and the resultant cycling of the system. Turning the switch to off stops the motor and removes power from. the solenoid switch, which connects the vacuum line to the object being cleaned.

For best results the solvent contained in tank 220 should be matched to the foreign matter present in the equipment to be cleaned. The gage cleaner is ideally suited to decontaminate gages, valves and peculiar piping configurations which have been used in reactor systems. When employed for decontamination, the apparatus should be filled with a radioactive contamination cleaning solution.

The novel cleaning method and apparatus which comprise the invention disclosed herein have been described by way of example rather than limitation. Accordingly, the practice of this invention may be accomplished by using diverse apparatus which are within the scope of this invention as specifically defined in the claims hereto appended.

We claim:

1. A method of cleaning the internal surface of an object having an open end and a closed end, comprising:

(A) rotating the object about an axis in the vicinity of said open end;

(B) introducing fiuid under pressure to the internal surface of the object from a first position when said open end is open downwardly in a plane through said axis to a second position when said closed end is approximately at it lowest position in the rotation; and

(C) evacuating fluid during the remainder of movement of the object about said axis.

2. A method as in claim 1, wherein the first position is defined when said open end of the object is positioned downwardly in a vertical plane through said axis.

3. A method as in claim 2, including repeating the steps of introducing and evacuating fluid.

4. A method as in claim 3, wherein said axis of rotation is generally horizontally disposed.

5. A method of cleaning the internal surface of an object having an open end terminating in a straight stem, a closed end, and a curved portion intermediate said ends comprising: orienting said object in a vertical plane; rotating said object in said plane in the direction of said closed end and about a center of rotation located on the elongated axis of said stem; evacuating said object during that part of its rotation from a first position wherein said closed end crosses a vertical line extended through said center of rotation to a second position wherein said axis of said stem coincides with said vertical line; introducing fluid under pressure during the remaining portion of rotation; and successively repeating said evacuating and said introducing fluid under pressure.

6. Apparatus for cleaning the internal surface of an object having an open end and a closed end, comprising:

(A) a source of fluid under pressure;

(B) an evacuating means;

(C) means for rotating the object about an axis located near its open end; and

(D) means connecting said open end of the object to said source of fluid at a first pre-determined position of the object during its rotation and to said evacuating means at a second pro-determined position of the object during its rotation.

7. Apparatus as in claim 6, wherein said means for rotating the object about an axis located near its open end includes a swivel union and pipe assembly.

8. Apparatus as in claim 7, wherein said means for connecting said open end to said source of fluid at said first position of the object and to said evacuating means at said second position of the object includes a cam assembly drivingly connected to said swivel union and pipe assembly.

9. Apparatus as in claim 8, wherein said means for connecting said open end to said source at said first position of the object and to said evacuating means at said second position of the object includes a valve for selectively interconnecting said source of fluid and evacuating means to said swivel union and pipe assembly.

10. Apparatus as in claim 6, wherein, said first position is defined as said closed end reaches any part of a straight line perpendicular to said axis and located within the plane of rotation of the object and said second position is defined as said closed end reaches another part of said line located within the plane of rotation of the object.

11. Apparatus as in claim 10, wherein said line is generally vertically disposed while said axis is generally horizontally disposed.

12. Apparatus for cleaning the internal surface of an object having an open end and a closed end, comprising:

(A) means rotating the object about an axis located near said open end;

(B) a source of fluid under pressure;

(C) an evacuating means; and

(D) means connecting the internal surface of the object to said evacuating means during rotation of the object from a first position wherein said closed end crosses a line being generally perpendicular to said axis and located within the path of rotation of said closed end to a second position wherein said closed end again crosses said line which again intersects the path of rotation of said closed end while introducing fluid from said source during the remaining portion of rotation of said closed end.

13. Apparatus as in claim 12, including successively repeating said evacuating and introducing fluid under pressure. i

14. Apparatus as in claim 13, wherein said means connecting the internal surface of the object to the evacuating means and for introducing fluid includes a swivel union, a valve for selectively interconnecting said source of fluid and evacuating means to said swivel union, a swivel pipe mounted in said swivel union for rotation therein, means driving the swivel pipe and a connector fixed on said swivel pipe and rotated therewith and receiving the object.

15. Apparatus as in claim 14, wherein said means connecting the internal surface of the object to the evacuating means and for introducing fluid further includes a cam drivingly connected to said swivel pipe for rotation therewith, together with a cam follower operatively interconnected to said cam and to said valve, thereby relating the operation of said valve to the position of said cam and consequently relating the operation of said valve to the position of said swivel, said connector and the object.

References Cited UNITED STATES PATENTS 2,493,120 1/1950 Eaton 134-21 2,597,896 5/1952 Oster 134-22 2,640,003 5/1953 Steenberg 134-21 2,814,575 11/1957 Lange 13421 X 2,845,934 8/1958 Payson 134-169 X 2,884,936 5/1959 Hillem'an et al. 13421 X JOSEPH SCOVRONEK, Primary Examiner. MORRIS O. WOLK, Examiner. J. ZATARGA, Assistant Examiner. 

